Some thermoplastic resin compositions such as flame-retardant ABS and flame-retardant PC/ABS, or reinforced thermoplastic resin compositions for plating bases made by reinforcing such thermoplastic resin compositions with fibers, are used as raw materials of a housing of electronic equipment such as a laptop personal computer and a portable device.
In recent years, a demand for electronic equipment to be thinner and more lightweight is getting stricter, and also a demand to be endurable against impacts and loadings while sitting inside a bag or such a container is being raised. In order to satisfy these demands, the resins used for a housing has to have high rigidity and impact resistance.
However, among conventionally employed housing materials for electronic equipment, non-reinforced flame-retardant ABS resins and flame-retardant PC/ABS resins have low rigidity and thus are not able to meet the recent demand of thickness reduction. In addition, glass fiber-reinforced resin compositions are not sufficient in the balance between the rigidity and the weight.
Furthermore, housings of electronic equipment need to have an electromagnetic interference shielding ability (hereunder, referred to as “EMI shielding ability”). Regarding a method for providing the EMI shielding ability, there is known a method in which a resin containing about 30% by mass or more of a carbon fiber is used.
However, if 30% by mass or more of a carbon fiber is contained, the molded article is likely to have bad appearance and the cost is prone to be incremented. On the other hand, if the content of the carbon fiber is less than 30% by mass, another means for providing sufficient EMI shielding ability has to be taken.
As for a molded article which can achieve lighter weight and reduced thickness as well as exhibiting the EMI shielding ability without impairing the mechanical strengths and the surface appearance, Patent Document 1 proposes a housing having a metal plating layer in a thickness of 5 μm or thicker on the surface of a molded article formed of a thermoplastic resin composition which includes a graft copolymer, a matrix polymer, and an inorganic filler.
In addition, as for a resin material for plating bases, Patent Document 2 proposes a thermoplastic resin composition including a graft copolymer, a matrix polymer, an inorganic filler, and a phosphate ester-based flame-retardant agent.    Patent Document 1: Japanese Laid-Open Patent Application No. 2000-349486    Patent Document 2: Japanese Laid-Open Patent Application Publication No. 2003-147154